4.2 CSA can be upgraded to 4.3 in place as long as you have RAID device. You need verify the hardware before upgrading
1, Reboot the CSA, to verify if you can find message as below screenshot.
2, Adaptec Embedded SATA HostRAID, means the SATA RAID Adapter was found
3, Two 232.88GB hard drives were found.
4, If you can't find 1 Locial Device(s) as last line, you need Press <Ctrl><A> to setup the RAID. At least 2 hard disks will be needed if you set as RAID1